The main objective of this study is to improve the knowledge of the coastal fish assemblage of 'Cinque Terre' Italian national Marine Protected Area (Ligurian Sea), focusing on the characterization of the fish fauna in the core zone A (no entry-no take). The study relates to the main sea-bottom types and bathymetric ranges, and evaluates the effect of the protection on fish abundance and size composition in this 5-yr-old MPA. Field activities were carried out in 2003 by means of visual census techniques. In the A zone, fish-assemblage composition are strictly related to depth and sea-bottom type. Recorded data did not permit detection of a clear reserve effect on fish fauna, probably due to the recent institution of the MPA. Several significant differences were detected only considering the size-class composition of target species.